The sugar-growing South African province of KwaZulu Natal is the driest it has been in over a century, according to data provided on Tuesday by the South African Weather Service, underscoring the scale of a drought scorching Africa's most advanced economy.

The drought, worsening because of an El Nino weather pattern, threatens South Africa's diverse farm sector, including its key maize crop. That may fuel food prices and inflation at a time when the central bank is in a tightening cycle.

The low rainfall and rolling heatwaves that have marked the start of South Africa’s summer come on the heels of 2014-15, which was the driest season since 1991-92, according to the data provided to Reuters.

In KwaZulu Natal province, a key political base for the ruling African National Congress (ANC) and a major sugar-growing region, the previous season was the driest since at least 1900.

The Weather Service measures seasonal rainfall by the Southern Hemisphere summer, so has not yet made a call about the current season’s severity.

"We are currently at the beginning of the summer season ... We do not exactly know how the current season would turn out," the Weather Service said in an emailed response to queries from Reuters.

Bleak vista

But things are clearly not looking good. The 2014-15 season was also the third-driest for South Africa as a whole since the early 1930s, when the country was hit by a historic drought in the midst of the Great Depression.

This season has made a blistering start. the Weather Service said Tuesday that a heatwave over four provinces, covering much of the maize belt, was expected to persist until Friday or Saturday.

The financial hub of Johannesburg this week imposed water restrictions on residents, which include not filling pools.

The dry conditions may extend into the autumn because of El Nino, a warming of ocean surface temperatures in the eastern and central Pacific that occurs every few years and affects global weather patterns.

Dry conditions last year cut South Africa's maize crop by a third. The weather outlook and historic troughs for the rand drove prices for yellow maize, used for animal feed, to 2015 highs over 3,000 rand a ton on Monday.

South Africa’s government last week urged livestock farmers to reduce the size of their herds as drought conditions suck moisture out of grazing land.

Agriculture Minister Senzeni Zokwana told parliament on Tuesday that 220 million rand ($15.4 million) would be made available immediately to provide cattle feed for subsistence and communal farmers.

"We feel their pain," he said.

In the short term, herd reductions may push down livestock and meat prices. But costlier maize – South Africa’s staple – will hurt poor and rural households.

This could have negative political consequences for the ANC in local elections next year.